Automatic gas cut-off.



PATENTBD SEPT. v1

V. E. CAMPBELL. AUTOMATIC GAS CUT-OFP.

APPLICATION FILED OUTLl, 1906.

gf l WWQZZfNk-M'- .A TTORNE Ys UNITED STATES PATENT OFFICE.

VICTOR E. CAMPBELL, OF PORTLAND, OREGON, ASSIGNOR-TO CAMPBELLS AUTOMATIC SAFETY GAS BURNER COMPANY, OF PORTLAND, OREGON.

AUTOMATIC GAS CUT-OFF.

'class employed for automatically cutting off the flow of gas through a gas burner in case the flame is accidentally extinguished, or in the case of failure to ignite the gas after the latter vhas been turned on. In devices of this class where a therinostatic element has been used for the purpose of controlling a gas cock turning mechanism it has been usual to so arrange the thermostat as to hold the cock closing mechanism from movement during the time the gas is lighted, and the thermostat is expanded. It has been found that where the heated thermostat is under constant strain during all the time the gas is lighted, there is considerable danger of moving the parts to inoperative position or effecting a permanent lengthening of the theimostatic element, so that the latter cannot always be relied upon.

In carrying out the present invention, one of the principal objects is to so arrange and connect the thermostat that the latter will be subjected to strain only when cool, and when in this condition there is less likelihood of permanent injury than where the strain is exerted on the heated thermostat.

A further object of the invention is to provide a device of this character in which the pressure exerted on the controlling devices shall be uniform at all times without regard to slight variations in temperature of the heated thermostat.

A still further object of the invention is to provide a device of this character in which the thermostatic element is heated by an auxiliary flame at one side of and below the tip of the burner, thus improving the appearance of the device and rendering it much more compact than where the thermostat is extended into or above the main flame.

With these and other objects in view, as will more fully hereinafter appear, the invention consists in certain novel features of construction and arrangement of parts, hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, pro- Specication of Letters Patent.

Application led October 15, 1906.

Patented Sept. 1, 1908.

Serial No. 339,027.

portions, size and minor details of the ,structure may be made without departing from the spirit. or sacrificing any of the advantages of the invention. Y

In the accompanying drawings Figure 1 is a side elevation of an automatic gas cut @if constructed in accordance with the invention, parts being broken away in order to more clearly illustrate the construction. Fig. 2 is anedge view of the same, the casing and other parts of the structure being shown in section.. Fig. 3 is a vertical section of the device on the line 3 3 of Fig. 2. Fig. 4 is an elevation looking from the side opposite that shown in Fig. 1. Fig. 5 is an inverted plan view of a portion 'of the device drawn to an enlarged scale.

Similar numerals of reference are employed to indicate corresponding parts throughout the several figures of the drawings.

The working parts of the cut off are supported principally by a vertically disposed tube 10 that preferably is of rectangular form in cross section, and is provided with a bore 11 through which the gas passes. The lower end of the tube is provided with a threaded socket 12 for the reception of a nip* ple on the gas supply pipe, and the upper end of the tube carries anipple 13 on which may be screwed a gas burner 14 of any desired type, the device being intended for use in connection with the ordinary ilat flame burners or any other type of burners such, for instance as the Bunsen, Welsbach, or other incandescent mantles or burners. Arranged within this tube 10 is a tapered plug .valve 16 which is provided at one end with a handle 17 or like member to be used in moving the valve port 18 into and out of alinement with the main gas passage 11.

Arranged in the wall of the tube 10 is a small gas passage 20 which terminates at the valve chamber, and the plug valve carries an auxiliary port 21 which is moved into communication with this passage when the gas is turned on, so that a small quantity of gas may 'flow outward through a burner orifice 22 arranged inside the main burner, in much the same fashion as a pilot light, this auxiliary burner being used for heating the' ther inostat element.

kSecured to the opposite sides of the tube 10 are plates 25 and 26 that preferably are iii the form of circular disks, and these disks have bearing openings for the arbors of a train of gears 27, the lirst gear 28 of this train being mounted loosely on the projecting end oi' the plug valve, and this gear is mutilated, forming two shoulders 29 which serve by engagement with a stop pin 30 to limit the turning movement of the plug valve when the latter' is automatically restored to its closed position. The mutilated gear engages with a pinion 31, the arbor oi which carries a ratchet wheel 32 which engages with a pawl 33 on one of the gears of the train 27, so that said ratchet wheel may be turned -from the mutilated gear Without transmitting rotative movement to the gear train.

Secured to the hub of the mutilated gear 28 is the inner end of a spiral spring 36, the outer end of said spring being secured to a bracket 37 that is carried by the plate 25, and when the mutilated gear is turned, the spring is placed under stress, and if allowed to operate, will transmit movement to all of the gears of the train, and will further serve to restore the valve to its closed position. The stem of the valve carries a projecting pin 39 which is arranged to engage a pin 40 that is carried by the hub of the mutilated gear, and each time the operating handle 1 7 is turned for the purpose of moving the valve to open position, the pin 39 will engage the pin 40, and the mutilated gear will be turned, and the spring' placed under stress. The mutilated gear and the spring will be held in the position to which they are adjusted by the means hereinafter described, while the valve is left free in order to cut oil the flow of gas to the burner.

The final arbor or shaft 43 of the gear train is extended through the plate 26 and carries a brake wheel 44 that is adapted to be engaged by a brake lever 45 that is pivoted on a pin 46. The brake lever carries a spring 47 which bears at one end against a pin 48, said spring tending at all times to Jforce the lever 45 into engagement with the brake wheel, and when these springs are engaged, the gear train will be held from movement under the influence of the spring. If, however, the brake lever is moved away from the Wheel, and the spring is under stress, the mutilated gear will be turned, and this movement will be transmitted through the pin 40 and the pin 39 to the valve, the latter being turned to closed position and cutting orf the low of gas to the burner.

Arranged to one side of the tube 10 is a small block 50 from which extends a tube 5l formed of readily expansible material, the upper end ofthe tube being closed. The upper portion of the tube is arranged immediately adjacent the auxiliary burner 22, and when heated will exp and, and when the burner is extinguished will contract. Arranged within this tube and connected to the upper.

end thereof, is a rod 53, formed of material having a` lower coeflicient of expansion than that of the tube. The lower end of the rod is bent outwardly, forming an arm 56 that is arranged over an arm 57 that is pivoted at one end to a bracket 584 depending from the block 50. The free end of the arm 57 extends through a slot 59 in the plate 26, and is arranged to engage the brake lever 45 at a point close to the pivot pin 46 of the latter.

lt will be seen that when the flame is lighted and the thermostat is heated, the rod 53 will be pulled up and the arm 56 will not be pressed against the arm 57, so that so long as the thermostat is heated, the spring 47 is free to act to force the brake lever 45 into engagement with the brake wheel 44 and then hold the train of gears from movement. If the gas is accidentally extinguished at thev burner, or if the gas is not ignited afterbeing turned on, the thermostat will contract, or will not be expanded, and the arm 56 will then press forcibly against the arm 57 and the latter will move thelever 45 from engagement with the brake wheel 44, so that the train of gears is free to operate and turn the 'valve to its closed position. From this it will be seen that during the time the thermostat is heated there is no strain on the thermostat and there is but little danger of the latter becoming inoperative. When the thermostat is notheated, it is better able to stand the strain without danger of injury, and it is during this time that the thermostaticelement is at work and holds the brake lever in inoperative position. The apparatus as a whole is preferably inclosed within a suitable casing 60 which may be ol globular or any other form and may be made ornamental or plain as desired.

1t will be noted that the thermostat is disposed entirely below the illuminating burner and that the pilot is interposed between the burner 14 and the thermostat so that the iame from the pilot will at all times contact with the thermostat and there is no danger of it being blown away therefrom. Attention is also called to the fact that the valve 16 simultaneously opens and closes the passages to the main burner and to the pilot.

Where the thermostat is used in connection with burners of the Welsbach or other type, it is preferred to make the thermostat long enough to extend up into the globe in such position as to be exposed to the heat from the main burner. In such cases the pilot lame or auxiliary burner is, of course, dispensed with.

1 claim 1. The combination with a tube having a burner at one end, and an auxiliary burner disposed below and adjacent the irst mentioned burner and disposed to receive gas from the tube of a plug valve for shutting off `the supply ol gas to the burners, a brake wheel, means operated by the movement ofthe valve for rotating the brake wheel, a spring pressed brake member dis osed to auvalve for cutting off the flow of gas to the burner, a brake wheel, a spring pressed lever disposed to automatically contact with the brake wheel to hold it against rotation, a pivoted arm bearing upon the lever, a thermostat disposed when cool to bear upon the arm to hold the lever out of contact with the brake wheel, said thermostat being disposed to be heated by a flame from the burner, and mechanism disposed to be actuated upon the cooling of the thermostat and the release of the brake wheel for operating the valve to cut off the gas supply to the main burner.

3. The combination with a main illuminating burner and a gas cock; of a closing spring for said cock which is placed under stress on opening movement of the cock, brake means for preventing operative movement of the spring and the closing of the cock while the gas is burning, a pilot burner, and a thermostat element supported solely at its base and terminating short of the main burner, said element and all parts connected thereto being disposed entirely outside of the field of light of the main burner, said thermostat element being adapted to be heated by a flame from the pilot burner and designed when cooled by the extinguishing of said flame to shift said brake means into position to permit closing of the cock.

4. The combination with a main illuminating burner and a pilot burner therebelow; of a single gas cock for simultaneously turning on or shutting off gas for the two burners, a closing spring for said cock which is placed under stress on opening movement of the cock, brake means for preventing operative movement of the spring and the closing of the cock while the gas is burning, and a thermostat element to be heated by a flame from the pilot burner and designed when cooled by the extinguishing of said flame to shift said brake means into position to permit closing of the cock, said thermostat and all parts connected thereto being disposed outsideof the field of light of the main burner.

In testimony that I claim the foregoing vas my own, I have hereto affixed my signature in the presence of two witnesses.

VICTOR E. CAMPBELL.

Witnesses:

N. CAMPBELL, Trios. E. HULME. 

